It is known as LADM to the Land Administration Domain Model, which managed to become ISO 19152 from 2012.
It is not a software, but a conceptual model that outlines the relationship between people and the earth; standardize what seems in each country is different and specialized; it is a materialized process of something that in the 2014 Cadastre was considered as abastracto. It seeks to avoid reinvention and re-implementation of the same functionalities by means of a base that is extensible and facilitates the institutions to communicate with standardized services in an international context.
Aware that geographers and people linked to geomatics need to know how to interpret models, we do this exercise to explain the origin of this standard from that moment when it was conceptualized as CCDM.
It is interesting that the LADM in part of its simple smoke poses that the administration of the land is a concept immutable in the time, has not varied in thousands of years:
It always consisted in the relationship that exists between man and the earth. No matter the culture where it is analyzed, history shows us something similar: People, such as the case of Adam and Eve who are delegates in community status to administer the Garden of Eden, with the right to be inside, responsibilities over what is there, and restrictions on not eating from a forbidden tree and expropriation rules in case of non-compliance.
That orchard is now called BAUnits, with a relationship of rights (RRR) with stakeholders, linked to people (Party) through a Source and in various forms of representation of the space entity (Spacial Units).
The truth is that as the systems of administration of property rights advance, there are complex cases that at the level of registration were always there but waiting to model their representation are cases such as:
A couple who are owners in a relationship 60% - 40% of a property that constitutes an 23 apartment on the 4 floor of a building, and that also includes the right to two parking spaces in the basement 1 and right in condominium with all residents from the building to the lobby of each level and a barbecue area on the eighth floor. Legally it is easy, it is only written but let's ask how we model it in a 3D cadastre, or at least in an 2.5 D.
With the LADM it is sought, that the way to model the concept of administration of land rights in IT tools is the same. Because the business is the same, it varies in little measure is the means and procedures that are very specific by country or discipline. The little habit of handling models makes it seem that the LADM is an astral wave only for computer scientists, perhaps because it is modeled in UML from classes and relationships, however it is part of the responsibility of the proposed surveyor in the 2014 Cadastre: «Long live modeling».
It is, therefore, a model of geospatial semantics, focused on the main functions of land administration:
- Keep the Object - Sujet - Right relationship updated (P - RRR - RO)
- And provide information on this record.
The model also seeks to facilitate the standardization of technological pressure that constitutes on the one hand the offer (Internet, spatial databases, standardized models, Free Code Licenses and GIS) and on the other hand a demand for services that take advantage of this technology (government electronic, sustainable development, electronic documentation and integration of public data and systems). One of the advantages of the LADM is that it can be adapted to each country, regardless of its legislation, the institutional separation of cadastre and registry, or the type of tool that will be used for automation. It suggests standard classes, and from there you can do specific classes for the country but in the end the concept is compatible.
The great victory of the LADM lies in linking the academic effort through the FIG with standardization initiatives that already existed, such as the LINZ and LANDxml of Australia / New Zealand, the National Integrated Land System of the Americans (formerly FGDC), the actions Of the European Commission on Science and Technology (COST), the ISO / TC211 Committee of the OGC and, above all, lobbying in areas of high incidence. And the hard part of making a standard is the imposition or reinvention of what others already specialized.
A little history
La FIG born in 2002, tries to appropriate this effort and lobby with recent initiatives such as the Inspire case and the IDE concept that take strength near 2003. This is how in short steps the LADM goes through different moments of presentation, discussion and adaptation of different versions that took the name of the city where they were presented, until becoming the 19152 ISO 2012:
- In April of 2002 the possibility of doing something is raised for the first time.
- In September of 2002 is presented in the OGC the version 1 called Noordwijk, soon in Delft in the COST Workshop.
- In March of 2003 the 2 version called Paris, that same year in the FIG and for this date the OGC announces the LPI
- In September 2003 presents the 3 version called Brno, in Poland. For this date the 3D multi-purpose cadastre extensions have been added. It was also presented at the European Land Information Service EULIS.
- In 2004 the 4 version called Bamberg, is presented in FIG events in Germany and Kenya.
- In 2005 is the 5 version called Cairo, in the FIG event of Egypt. By then, the standards that the OGC managed through the ISO / TC 211 Committee have been integrated; Although this committee has published more than 50 standards of great interest in the geomatic field, the LADM takes from here two: Geometry and Topology). Also for this date it becomes Inspire's cadastral data specifications.
- 2006 presents the 6 version called Moscow, which is this version of which we spoke in Geofumadas in the article «A standard model for cadastre«. This already includes Building RRR and the Part of parcel is explained separately in a full-purple class.
From 2006 to 2008 the effort is focused on accreditation as a standard.
- In October of 2006 already presents the Version 1.0 although by that date was called CCDM (Core Cadastral Domain Model).
The process of making it an ISO standard, by means of different meetings of discussion, extension and specific definition of claeses; Ends in 2012 by means of Chrit Lemmen's doctoral thesis in 2012.
There is still much, several countries have already adopted the norm, although much remains ahead. After this standardization effort has come a process of implementation and landing to reality, where links have been made with the JRC (Joint Research Center of European Commission) and UN-HABITAT (United Nations Agency for Human Settlements) to be applied in projects linked to territorial management. This has seen examples materialized in different countries, highlighting the case of the STDM (Social Tenure Domain Model) which is considered a specialization of the LADM, by FAO is the Flossola and in Honduras the SIGIT prototype that now seeks to scale up SINAP.
Explanation of the Model
The exercise of this article is that we try to understand the origin of the LADM based on a graphic scheme. I am trying to use colors similar to the model classes, which already in the approved standard separate in yellow the legal part, in green the person, in blue the objects, in pink the topography and in purple the topology. Surely using icons will bring us some relationship by association but I insist; We have to learn to understand models. By passing the mouse over the objects, its meaning is shown.
[hsmap name = »ladm»]
The main entities.
The scheme starts from the relationship between the three main entities:
- Stakeholder (Subject), in the norm defined as Party
- Object of law, which in this case removes the archaic concept of cadastral parcel and takes it to territorial object. In the standard is called BAUnit, and its geometry Spatial Unit.
- Law, relationship that links the person with the object, in the standard defined as RRR.
The model links them by means of the source. This can be documentary or factual; it's just reality. The rest are possible cases:
- Not only is there an owner, but a group of heirs, one of them with life imprisonment,
- The plot has a flat, but it is on paper and has no georeference,
- The subdivision has not been determined, but only the percentages of law ... one of the brothers already sold his right to four more people,
- This portion sold has a mobile phone tower with an access server,
- Part of the plot is affected by a protected area under special regime,
- One of the brothers is a minor, so he is legally represented by his gay mother ...
Whether or not there is a map, whether or not it is legal, whether or not it is in accordance with the procedures, it is a reality that is there. Therefore, the LADM accepts that reality be recorded in a controlled manner, indicating the physical and legal situation.
The interested party (Party)
See that here the simple "subject" is extended to the different people who intervene in the transactions. So we have:
- The individual person
- The legal entity, as in the case of an institution or company
- The grouping of people, such as the case of an indigenous group, an association, peasant group, etc.
- The person or institution that certifies the right, such as the lawyer's case
- The person or institution that certifies the mortgage, as in the case of a bank or financial institution
- The person making the measurement document, such as the surveyor.
The relationship of rights (RRR)
Here, in the traditional cadastre, it was only a type of tenure. But the model is extended so that the different possible conditions of relationship of law and administrative burdens can be adapted:
- Mortgage or encumbrance
- The affectations, which can be Restrictions, Attributions and Responsibilities.
- The tenancy relationship with the source.
The Object of Law
Here there are different levels of classes, but all basically part of the object that is called administrative unit (BAUnit). See that this is an abstraction of the object, whether or not we have a map or document.
This is because in reality there is an object, which will gradually be documented but the BAUnit part of that and in a first instance are the scenarios "not georeferenced":
- The non-real object, that is, what can be removed from the plot, such as the case of a mobile home, a telephone antenna, etc.
- An identifier of a real estate base
- A non-georeferenced document
- A physical address that identifies a house within a building, and this can be beyond the apartment level within a building.
Then there are the BAUnits that have a spatial identification, among these can be:
- The unstructured plot (part of parcel), which can be a point, a set of points and boundaries.
- The structured plot, which can be a unit, or several in relation to a single property.
One of the advantages of adopting the LADM model is that no data is negligible, there is no good or bad cadastre, only a reality represented. The administrative units exist and can be improving of precision from:
- A base of taxpayers of a municipality that are only sworn statements stored in Excel.
- Later they can have a coordinate, with what a dotted cadastre is a primitive but valid solution.
- Then you can have plots, but not with high precision.
Everything closes in the spatial identification of the plot, with different levels of representation for a simple reason "in physical reality the object is only one". It is also important that not only private law is reflected, but also public law, as in the case of a protected area or spatial entities defined in different legislations as a flood area that causes an affectation of the plots.
Representations of the object.
This is a series of special classes, which allow defining different types of topographical representations of the same object, that is why they are linked to the source.
Here the important thing is that the minimum unit of measurement is a point, which is the responsibility of the surveyor. They detail different conditions for 2D and 3D.
In the case of two dimensions, a point, then the boundary in arc-node relationship and then the shape in closed geometry. The same exists for 3D although here is another case that is an 3D object not composed of faces.
The linkage of the topographic representation is through the source, taking into account that there will always be a document that defines a greater precision that can not be drawn in the cadastral parcel as part of a context.
In conclusion, the LADM is a standard that must be known. It is a materialization of the abstract raised in the 2014 Cadastre to which we have already arrived; although with many achievements in the technological and academic part with many challenges in the institutional and normative part.